High pressure cylinder



July 22, 1941. o. MINDER HIGH PRES SURE CYLINDER Filed Oct. 20, 1939 2.Sheets-Sheet 1 MV/lI/Ifld. I I III ATTORNEY-5 Patented July 22, 1941UNITED STATES PATENT, OFFICE HIGH PRESSURE CYLINDER out Minder,Winterthur, Switzerland, assignm- 'to Sulzer Frres, Socit Anonyme,Wintei'thur,

Switzerland Application October 20, 1939, Serial No. 300,405 InSwitzerland October 27, 1938 3 Claims.

This invention relates to high-pressure cylinders, and particularly tocylinders of the type employing a single acting piston. The highpressure cylinder of the invention comprises at least two parts, onepart being at the head-end where the fluid medium undergoing compressionis subjected to the greatest pressure; the other part (hereinaftercalled the low-pressure'cylindel -portion is connected to the head-end,portion and extends to the vicinity of the lower dead point of thepiston, the pressure in this portion of the cylinder being relativelylow. The invention contemplates the provision of an improved cylinder.for the compression of fluid media at pressures, for example, over onethousand atmospheres capable of resisting corrosion resulting from theconditions prevailing in certain portions of the cylinder.

Repeated attempts have been iacture such compression cylinders, whichare subject to high stresses, of steel which'is suitable forj tempering.However as these, without exception, for construction reasons show very-great differences with respect to the cross sections and materialaggregations or agglomerations cannot be avoided, whereby atemperingwhich is uniform and free from stresses is impossible, theseattempts did not lead to the resultexpcted. In

accordance with the invention, therefore only that part ofthe workingsurface which is e posed to corrosion is made of steelsuitable-fortempering. 7

In subjecting certainfluid media to extremely high pressures incylinders, there is a relatively rapid corrosion of the cylinder in thevicinity of the lower dead point of the piston caused by a corrosionphenomenon generally attributed to accumulated acid residues. Therelatively low temperature and pressure at thispart of the cylinder seemto produce conditions most favorable to corrosion. The'invention aims toprovide made to manu- The apparatus illustrated in Fig. 1 comprises ahead-end cylinder-portion I formed of a rela-- tively thick pie'ce of,metal, for example, steel,

to withstand the excessive pressures when the piston 2 is in theposition shqwn at the upper end of its compression stroke. The head-endportion I has suitably mounted therein a suction valve 3 and a pressurevalve 4 which are connected to intake and exhaust'conduits 5 and 6respectively, The low-pressure cylinder-portion I 0 is so connected tothe head-endportion I as to form a continuous cylinder for thereciprocation'therein of the piston 2.' The cylinder portion III hasrelatively thin walls in comparison with the relatively thick walls ofthe head-end portion I and is formed 0! a heat treated corrosionresisting alloy, such as stainless steel or the like.

. The .low-pressure'cylinder is attached to or I mounted upon a frame IIand has a stufling box I2 attached to the lower outside portion of the 5cylinder I 0. The 'stufllng box comprises a packing I3 and a bushing IImade, for example, of

\ bronze, which butts up against the cylinder and a high-pressurecylinder in'which the head-end portion is relatively thick and alow-pressure cylinder-portion. having a relatively thin wall formed of aheat treated metal capable of resists ing the corrosive action justdescribed. The lowpressure cylinder-portion, which is the part exposedto the most active corrosion, is made in the simplest possible form, forexample, as a solid of revolution. symmetrical, or with equal thicknessof wall. It is preferably formed of a corronon resisting steel alloy,for example: I

or a steel containing one or' more of the following metals: nickel,chromium, vanadium, aluminum, silicon, manganese, molybdenum. copservesas a guide for the piston rod 2. The stuffing box has a cover Ii-iorcompressing'the packing I3 by means of the bolts I6. I -.As shown in thedrawings, the piston I is in the upper dead-end pist'onleaving aclearance I! in which the fluids are compressed. Wh piston moves on thedownward stroke. it r ches the lowerdead-end piston shown in. the dottedlines within the bushing II. The low-pressure cylinder portion shown inFigs. 2 and 3 has upper and lower flanges II and 0 2|, respectively..ylhich are square in cross-section and the lower flange is larger indiameter.

but of the same thickness as the upper flange. The central body portion22 is'preferably cylin- -drical.

'55 The low pressure cylinder-portion shown ,in-

Figs. 4 and 5 comprises upper and lower flanges the 25 and 26,respectively, which are of approximately the same thickness but thelower flange is of larger diameter. The central portion 21 iscylindrical as are the flanges, this cylinder being formed as a solid ofrevolution.

The low-pressure cylinder-portion shown in Fig, 6 comprises upper andlower flanges 30 and 3|, respectively, in the central portion 32. Thiscylinder is made symmetrical with respect to they plane 33.

The low-pressure cylinder-portion shown in Fig.3 comprises upper andlower flanges 35 and 36, respectively; and a central portion 3"1'. Thiscylinder is made as a symmetrical solid of revolution with equalthickness of wall.

In view of the different kinds of metals used in forming the cylinderand stuffing box, there is a tendency for electrolysis to be set up withresulting decomposition of one or more of the metals. In forming the lowtemperature cylinder portion of the heat treated corrosion resistingmetal, the destructive action resulting from electrolysis is veryefiectively suppressed.

I claim:

1. A high-pressure cylinder which comprises a head-end portion wherein afluid medium undergoing compression is subjected to the highest pressureattainable in the cylinder, valves for the intake and exhaust or gasmounted in the headend portion, a low-pressure portion having relativelythin walls with respect to the thickness of the walls of the head-endportion and a flange at each end, saidlow-pressure portion being formedof heat treated alloy steel which is highly resistant to the corrosiveaction in the cylinder and being connected by means of the flange at oneend tothe head-end portion and by means of the flange at the other endto a stuffing box, a piston reciprocable in ,the high-pressure cylinder,and means operatively connected to the stufiing box to guide the piston.

2. A high-pressure cylinder according to claim 1 in which the centralportion of the low-pressure portion of the cylinder is about the 'samethickness as the flanges.

3. A high-pressure cylinder according to claim 1 in which thelow-pressure portion is symmetrical with walls of uniform thickness.

o'r'ro MINDER.

